The present invention pertains to a toilet flushing reservoir system, and in particular to a reservoir therefor.
The most widely used toilet flushing systems include a reservoir or tank which is connected to a water main through a water line, the admission of water into the tank being controlled by a valve, which valve is operated by a float carried by an arm extending from the inlet valve. The flow of water from the tank, into the toilet bowl, is controlled by a ball valve, which is usually of soft material, being pressed into engagement with the valve seat by the head of water in the tank, the ball valve being lifted from its seat by a suitable mechanism, such as a lever. Such apparatus is known to suffer from a number of deficiencies, including the taking up of a significant amount of floor space by the tank, as well as the unsightliness of the tank and associated plumbing. The soft ball valve will deteriorate after a period of use, and such tanks have generally been found to be expensive in that they require a substantial amount of machining of the parts, particularly the inlet valve, as well as requiring expensive casting operations. In addition, rather complex and expensive assembly operations are required. Further, the known, above described systems are prone to leaking, and the tanks themselves are heavy, usually being made of cast ceramic, and are therefore expensive to ship from the place of manufacture to the place of use.
There have also been proposed other toilet flushing reservoirs, some of which have involved generally linerally extending pipes or tanks, which were placed within a wall. These reservoirs have generally operated on the principle of an air cushion, trapped at the top of the body of water within the pipe, or pipes, or tank. This trapped air was compressed when the water flowed into the reservoir, from the bottom, and when the outlet valve was operated, the trapped air expanded, to assist in forcing the water into the toilet bowl, this assistance being in addition to the gravity-caused water flow. The trapped-air or air cushion type of reservoir has not met with wide spread usage, because of a fundamental deficiency. That is, the trapped air over a period of time becomes entrained in or absorbed by the water, particularly since there are sequential bodies of water with which the air comes in contact. The absorption or entrainment of the air ultimately diminishes the amount of air in the air cushion above the body of water, so that the available force is gradually diminished, until, ultimately, the amount of air remaining is so small as to be unsatisfactory in providing the volume and velocity of water flow from the reservoir.
Recognizing the deficiencies of the air cushion type of reservoir, a proposal has been made to substitute a spring device for the air cushion, but such a spring device cannot be economically made, is liable to breakage after an extended period of use, and must be expensively made in order to be long lasting.
A still further proposal of the prior art provided an upper tank into which water was admitted, the tank having an outlet valve operated by a lever, the tank discharging into a lower tank, into which pipes with lateral openings extended, which pipes communicated with the toilet bowl. This apparatus required a dash pot for satisfactory operation, which dash pot is liable to become ineffective after a period of use. Further, such a construction provided an undesirable three stage flushing operation including a slow first stage, a fast second stage and a slow third stage.